GLACIAL WATERS IN THE LAKE ERIE BASIN 



39 



The figures for the outlets are taken from the map contours and are 

 not precise. Accurate measurements would probably show closer 

 correspondence than this tabulation. When we realize the con- 

 siderable variation in altitude of the - water-leveled plains with 

 reference to the water surface, and the fact that the lake waters were 

 slowly drained down through all the levels from the highest to the 

 lowest, the above correspondence is very striking and conclusive. 

 It shows a harmony of facts indicating that the theory is sound. 



Passing east from the Cattaraugus we shall find that the same 

 series of parallel valleys which held lakes of the earlier class [see 

 p. 35] also held lakes of this group, and with lowering surfaces as 

 shown by the numerous channels already described as lying across 

 the ground between the valleys. It seems unnecessary to recapitu- 

 late the lakes by the former names; and it is not desirable to give 

 distinct names merely in recognition of changing outlets and different 

 levels until we can describe them with greater detail and precision 

 than is possible without the topographic sheets. In each valley a 

 good observer can probably find sufficient lake and stream phenom- 

 ena to yield an interesting history when translated by competent 

 study and correlation. 



In the Tonawanda valley the Attica lake was the successor of the 

 Varysburg-Johnsonburg lake. The overflow channels of this water 

 have already been described as the numerous strong channels lying in 

 the broad belt north and south of Darien and Darien Center. Delta 

 plains and terraces should occur along the sides of the valley at 

 various levels. It would seem that they should be stronger at 

 about 900 to 1050 feet, or correlating with the stronger overflow 

 in the region of the Lackawanna and the Erie Railroads; but the 

 conspicuous delta plain of the State Asylum farm at Varysburg, at 

 1200 feet, must correlate with some other outlet. The delta east 

 of Alexander, at 950 to 920 feet, was built when the waters had outlet 

 along the line of the Lackawanna Railroad. When the outflow 

 was near Batavia the lake was too shallow and restricted to reach up 

 the valley beyond Attica. 



The theoretic succession of waters in the Tonawanda valley may 

 be outlined as follows: 



1 North Java lake. The outlet not determined, but at about 



1600 feet. 



2 Varysburg-Johnsonburg lake. Outlet west of North Java, 

 i5io± feet. 



3 Same lake, second stage. Flooding Humphrey Hollow (Cayuga 



valley). Outlet near North Sheldon, at 1500 to 1400. 



